C-OnSite® for intraoperative 3D control of pedicular screw positions

Background

Two-dimensional image guidance and navigation can help to reduce the number of misplaced pedicle screws, but do not completely prevent misplacement. This experimental, retrospective, non-inferiority study was designed to evaluate and compare the efficacy of a novel 3D imaging technique versus conventional postoperative CT-scan, for intra-operative determination of pedicle screw position accuracy.

Methods

The capacity of C-OnSite® to intraoperatively assess screw placement was evaluated in 28 clinical cases and 23 deliberately misplaced screws in a cadaver model, and compared to placement accuracy determined by standard CT. The position of each implant, as viewed by both modalities, was graded by three neurosurgeons, one orthopaedic-surgeon and one radiologist. The intermodal variance determined the difference between CT- and C-OnSite® results for each observer, while the inter-observer variance measured the difference between ratings of the same modality by different observers.

Results

C-OnSite® successfully assessed 120/138 screws (25/28 cases). Mean procedural fluoroscopy time was 132?±?51s, and 40?±?16s per C-OnSite® scan. The average inter-modality variance was ,15 % with mismatches >1° between C-OnSite® and the gold-standard imaging technique in only 2 % of the comparisons. Average inter-observer variances were about similar (12 % for CT and 18 % for C-OnSite®), with deviations of >1° reaching 1 % for CT and 3 % for C-OnSite®. Individual variances between experienced only observers differed even less.

Conclusions

C-OnSite® is a feasible, reliable and intuitive means of intraoperatively visualizing pedicle screw positions and might render the majority of postoperative CTs superfluous. C-OnSite® might help avoid re-operations for screw re-positioning.     

Biomaterial-based bone regeneration and soft tissue management of the individualized 3D-titanium mesh: An alternative concept to autologous transplantation and flap mobilization

Three-dimensional augmentation in severely atrophic bone and after cancer resection is a challenging clinical indication that is mostly solved using autologous bone transplantation. The development of the digital technique along with the additive manufacturing and three-dimensional (3D) printing opened new avenues for reconstructive oral and maxillofacial surgery. Therefore, patient-specific titanium mesh is a novel means of stabilizing the augmentation region using particulate bone substitute materials (BSMs) combined with autologous bone as a minimally invasive concept. However, dehiscence is a frequently reported complication in this field. Therefore, the aim of the present case series was to introduce a biomaterial-based regenerative concept in terms of exposed open healing to overcome the dehiscence related to 3D-titanium meshes. Additionally, this case series presents a novel protocol using a combination of xenogeneic BSMs with an autologous blood concentrate system (platelet-rich fibrin [PRF]) and collagen matrices without any autologous transplantation. Seven patients with alveolar ridge atrophy with different etiologies (cancer resection, severe atrophy after tooth loss, aplasia, trauma, implant infections) were treated using the open-healing concept. Therefore, after 3D augmentation using the described biomaterials, the flap margins were approximated, and the gap between the flap margins was bridged using a collagen matrix loaded with liquid PRF that was then covered by either a PTFE-based membrane or sterile latex. No periosteum splitting was performed at any time point. After a healing period of 4–8 months, all patients received dental implants as virtually planned. Bone biopsies were performed during dental insertion for histological evaluation. The augmentation area displayed a vital and well-vascularized newly formed bone that incorporated the BSM granules to build a hybrid bone. Additionally, open healing resulted in newly formed soft tissue without any signs of scar formation or fibrosis. The regenerated soft tissue was used to build a new flap during implant insertion and showed good functional and aesthetic results after implant insertion. The open-healing concept of the regeneration of the soft tissue along with bone tissue to regenerate a harmonic implantation bed is a minimally invasive intervention without periosteum splitting or large flap mobilization. However, further controlled clinical studies are needed to evaluate this concept in a larger patient cohort to outline the potential clinical benefit.     

Cost analysis and effectiveness comparing the routine use of intraoperative fluorescent cholangiography with fluoroscopic cholangiogram in patients undergoing laparoscopic cholecystectomy

Background

Despite the standardization of laparoscopic cholecystectomy (LC), the rate of bile duct injury (BDI) has risen from 0.2 to 0.5 %. Routine use of intraoperative cholangiography (IOC) has not been widely accepted because of its cost and a lack of evidence concerning its use in preventing BDI. Fluorescent cholangiography (FC), which has recently been advocated as an alternative to IOC, is a novel intraoperative procedure involving infrared visualization of the biliary structures. This study evaluated costs and effectiveness of routinely implemented FC and IOC during LC.

Materials and methods

Between February and June 2013, the authors prospectively collected the data of all patients undergoing laparoscopic cholecystectomy. We retrospectively reviewed and compared the use of FC and IOC. Procedure time, procedure cost, and effectiveness of the two methods were analyzed and compared. The surgeons involved in the cases completed a survey on the usefulness of each method.

Results

A total of 43 patients (21 males and 22 females) were analyzed during the study period. Mean age was 49.53 ± 14.35 years and mean body mass index was 28.35 ± 8 kg/m². Overall mean operative time was 64.95 ± 17.43 min. FC was faster than IOC (0.71 ± 0.26 vs. 7.15 ± 3.76 min; p < 0.0001). FC was successfully performed in 43 of 43 cases (100 %) and IOC in 40 of 43 cases (93.02 %). FC was less expensive than IOC (US$14.10 ± 4.31 vs. US$778.43 ± 0.40; p < 0.0001). According to the survey, all surgeons found routine use of FC useful.

Conclusion

In this study, FC was effective in delineating important anatomic structures. It required less time and expense than IOC, and was perceived by the surgeons to be easier to perform, and at least as useful as IOC. Further prospective studies are warranted to evaluate the effectiveness of FC in decreasing BDI.     

Cutaneous squamous cell carcinoma in two pediatric lung transplant patients on prolonged voriconazole treatment

Oral voriconazole is commonly used for treatment and prophylaxis of invasive fungal disease post‐LTx. Development of cutaneous SCC has been described in adult LTx recipients, although it is extremely rare in children. We describe two Caucasian children who developed cutaneous SCC beyond three yr post‐LTx. Both developed severe photosensitivity, actinic keratosis and required curative surgical excision of the cutaneous SCC lesions. Neither patient developed metastatic lesions nor had allograft dysfunction as a result of the SCC or the change in medical treatments. The effect of voriconazole on the development of malignant skin lesions is discussed and a recommendation on dermatologic surveillance, preventive measures against phototoxicity and early treatment of SCC are provided.     

Relation of urinary tract infection and vesicoureteral reflux to scars: follow-up of thirty-eight patients

A prospective study compared the outcome of vesicoureteral reflux and recurrent urinary tract infections in children (3 boys, 62 girls) who received medical prophylaxis or underwent surgical correction of reflux. Thirty-eight children returned for reevaluation 6 to 13 years (average 9.5 years) after entry. There was a marked decrease in prevalence and severity of reflux. At entry, 13 had significant scarring that had progressed at follow-up. New scars were documented by dimercaptosuccinic acid scan at follow-up in eight children on the medical regimen and two who were initially treated with surgical correction of reflux. Four patients with high-grade sterile reflux were followed for 6 to 10 years without the development of cortical scars. Our data support the role of urinary tract infection and vesicoureteral reflux, but not sterile reflux, in the pathogenesis of chronic pyelonephritis and reflux nephropathy.     

Management of the acute respiratory distress syndrome

Significant advances have occurred in the knowledge of the pathogenesis of ARDS. It is now recognized that ARDS is a manifestation of a diffuse process that results from a complicated cascade of events following an initial insult or injury. Mechanical ventilation and PEEP are still important components of supportive therapy. To avoid ventilator-associated lung injury there is emphasis on targeting ventilator management based on measurement of pulmonary mechanics. For those with resistant hypoxia and severe pulmonary hypertension adjunctive modalities, such as prone positioning and low-dose iNO, may provide important benefit. Alternative modes of supporting gas exchange, such as with partial liquid ventilation and extracorporeal gas-exchange, may serve as rescue therapies. Advances in cell and molecular biology have contributed to a better understanding of the role of inflammatory cells and mediators that contribute to the acute lung injury and the pathophysiology of the syndrome that manifests as ARDS. Based on this new understanding, the potential targets for intervention to ameliorate the systemic inflammatory response have proliferated. Examples include the cytokine network and its receptors, antioxidants, and endothelins. Apart from the challenge of testing these agents in experimental models, it seems likely that determination of the optimum combination of agents will become an equally important endeavor. A particular challenge is to develop better methods of predicting which of the many at-risk patients will go on to full-blown ARDS and MODS, thereby targeting subgroups of patients most likely to benefit from anti-inflammatory therapies. Similarly, the adverse effects of immunosuppressive therapy may be diminished by improved, perhaps molecular, techniques to detect microbial pathogens and permit differentiation between Systemic inflammatory response syndrome and sepsis.